Hopefully EVs are being purchased to replace existing ICE cars, in which case the falling price is a good thing since it makes them more available at lower price points. Replacing a car with one that is cheaper to run and produces less emissions is usually a good thing.
If people are buying (and storing, and fueling) EVs in addition to their collection of ICE cars, that's probably a separate issue about overconsumption.
People buying new EVs might be bad for environment though.